Garage Conversions: Chino vs Ontario
How do garage conversions rules compare between Chino, CA and Ontario, CA?
Chino has fewer restrictions than Ontario.
Chino, CA
San Bernardino County
California Gov. Code §65852.2 (now re-codified by SB 477 at Gov. Code §66310 et seq.) preempts local bans on converting an existing garage into an Accessory Dwelling Unit. Chino adopted a conforming ADU ordinance on March 17, 2020 (Chino Municipal Code Title 20). Garage-to-ADU conversions are permitted ministerially, replacement parking is NOT required when a garage is converted to an ADU, and approval must be issued within 60 days of a complete application.
View full Chino rules →Ontario, CA
San Bernardino County
Ontario allows garage-to-ADU conversions under Gov Code 65852.2 with no replacement parking required. Non-ADU conversions to living space still need a building permit and must replace covered parking.
View full Ontario rules →Key Facts Comparison
| Fact | Chino | Ontario |
|---|---|---|
| State preemption | Gov. Code §65852.2 (now §66310 et seq. per SB 477) — local bans preempted | - |
| Chino ADU ordinance | Adopted March 17, 2020, CMC Title 20 | - |
| Replacement parking | NOT required when garage converts to ADU | Not required for ADU |
| Approval timeline | 60 days ministerial review of complete application | - |
| Owner occupancy | Not required for ADUs permitted 1/1/2020 – 1/1/2025 | - |
| ADU conversion | - | Gov Code 65852.2 |
| Permit type | - | Building permit required |
| Egress | - | Bedroom window or door |
| Non-ADU conversion | - | Parking must be replaced |
Highlighted rows indicate differences between cities.
Chino FAQ
Can Chino deny my request to convert my garage into an ADU?
No, not categorically. State law (Gov. Code §65852.2 / SB 477 re-codification at §66310 et seq.) preempts local bans on garage-to-ADU conversions. Chino's March 17, 2020 ordinance under CMC Title 20 implements this state mandate.
Do I have to add a new driveway or parking space?
No. State law specifically exempts garage-to-ADU conversions from replacement parking requirements (Gov. Code §65852.2(a)(1)(D)(xi)).
How long does the City have to act on my application?
60 days from a complete application. ADU permits in California are ministerial — no discretionary hearing, no CEQA.
Ontario FAQ
Can Ontario make me add another parking space when I convert my garage to an ADU?
No. State law prohibits requiring replacement parking when a garage is converted to an ADU, even if the original garage provided the home's only covered parking.
Do I need a permit to turn my garage into a home gym?
Yes. Any conversion of garage space to living space requires a building permit, insulation, egress, and often a change-of-use review even if it is not an ADU.
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